I started work on Ch 20 as I finished up Ch 16 for 2 main reasons:
1) The first is that I have the Eureka foam cut for the winglets in boxes that are about 4 years old and the cardboard is starting to rot. That's not a big deal except that I'm having to move these boxes around in my house from different rooms and storage spaces as kids come and go to college, and each time they move they become more damaged (these are not small boxes). I wanted to reduce the storage volume (extra foam) and also get these winglets built and glassed so they are less vulnerable to dings in their foam form.
2) I'm also improving my skills with the glass and was ready to take on an airfoil in total, since I'd gotten the wings and canard in skin form from David Pierce. The weather late winter/early spring in Austin was unusually warm (perfect low 70's for working with epoxy as well, so it seemed like a good time to do this.
I plan to get the winglets built and stored until I get a hangar. Then I'll attach them to wings, cut and finish the rudders and continue on. Packing trailer to move to hanger is WAY easier without the winglets on the wings.
1) The first is that I have the Eureka foam cut for the winglets in boxes that are about 4 years old and the cardboard is starting to rot. That's not a big deal except that I'm having to move these boxes around in my house from different rooms and storage spaces as kids come and go to college, and each time they move they become more damaged (these are not small boxes). I wanted to reduce the storage volume (extra foam) and also get these winglets built and glassed so they are less vulnerable to dings in their foam form.
2) I'm also improving my skills with the glass and was ready to take on an airfoil in total, since I'd gotten the wings and canard in skin form from David Pierce. The weather late winter/early spring in Austin was unusually warm (perfect low 70's for working with epoxy as well, so it seemed like a good time to do this.
I plan to get the winglets built and stored until I get a hangar. Then I'll attach them to wings, cut and finish the rudders and continue on. Packing trailer to move to hanger is WAY easier without the winglets on the wings.
Glassing the Skins:
At this point in my build experience I'd seen the dialog and adoption by respected builder/flyers about using the hard shell method of skinning foam prior to glassing and it's superior peal resistance, as well as the reduced leaching of micr spheres from the wet micro layer into the epoxy of the glass layers when doing everything at once. So: time to learn how to do it. I started with the lower winglets since they were smaller and in my opinion small boo boo's there would impact performance less than on the larger upper foils/rudders. A good reference for this method is given by a number of very good builders and I'll just repeat the link here: hard shelling. I followed the method and had no problems. As long as you plan for a good sanding of the hard shell when it cures (I didn't have the flexibility in time to pick an optimal partial cure to start the glass layup) the method works great and I felt the quality of the overall layups was extremely good (smooth, clear, no bubbles, and ample ability to move the first layer of fabric without dragging around micro). I will say that this takes more time since there are 2 cure cycles rather than one for each side, but I think it's worth it for the airfoil shapes in particular. Finished the upper winglets per Plans with the antennas embedded as shown to the right. The main tip I feel might be useful to new builders is to plan for digging out plenty at the coax/ferrite coils intersection at the antenna. You really want this to be flush and then micro it over. I used Dremel with a router attachment head to cut the trench for the coax (after hard shelling) and it worked great. I fell really good about how these foils came out. They are smooth and clean and the trailing edges are nice and smooth and strong. I'll need to do a little more fill on the trailing edge where you micro the depression from the Rutan method, and that's fine. Now they go into storage until I go to hangar (easier to store and transport wings and winglets without them being connected). Unless the plan changes later and I need more time at home to work... 3/18/16 |
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